The Air NZ tender came in the cheapest but as well Forstaff has been having trouble with unions in Victoria and QF's response to the unions has been that if they keep driving up costs then QF would send the maintenance overseas - obviously this was not an idle threat.
The contract with Air NZ also covers a very substantial refurbishment of the 6 B747-300 classics.
If QF does end up buying a minority stake in Air NZ then they would use the lower staff costs of Air NZ (based mainly on the currency exchange rate) to force lower salaries on the Australian staff. Not a pleasant prospect for many of us.